(a) Field of the Invention
The present invention relates to a method and an apparatus for monitoring a laser welding bead, and more particularly, to a technology capable of determining in real time whether or not welding defects are generated during laser welding.
(b) Description of the Related Art
Because laser welding has excellent welding quality, has a fast processing speed, and is applicable to a hetero-junction of various materials, it has been used in various industry fields.
Because quality monitoring of a laser welding bead by an existing tailor welded blanks (TWB) process is generally performed by a visual quality inspection by a worker, a material rupture caused by missed detection of a pinhole in a post-process has frequently occurred. Therefore, in order to solve the problem described above and improve welding quality, an apparatus capable of automatically determining a welding quality state by observing a welding bead shape in real time when the welding is performed necessarily needs to be attached.
As a conventional art, various technologies for monitoring the welding state have been suggested. However, the suggested technologies have drawbacks that the monitored results are somewhat inaccurate and there is a limitation in performing real time monitoring, because signal distortion caused by background noise is severe, a filter configuration is complex, or whether or not the defects are generated is determined by a simple dimension comparison. In addition, the suggested technologies have a drawback that there is a limitation in using for an actual field or a limitation in using for various welding bead shapes.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.